Method and apparatus for receiving system information

ABSTRACT

A method for receiving system information performed by a user equipment (UE) is provided. The method includes receiving a system information block type 1 (SIB1) from a cell. The SIB1 includes a first list. The number of entries in the first list ranges from one to the number of public land mobile networks (PLMNs) operating the cell. Each entry in the first list includes an indicator corresponding to a PLMN operating the cell and access control information of the PLMN operating the cell.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application claims the benefit of and priority to aprovisional U.S. Patent Application Ser. No. 62/670,227, filed on May11, 2018, entitled “Method and Apparatus for System Information Requestand Response,” with Attorney Docket No. US73667 (hereinafter referred toas “US73667 application”). The disclosure of the US73667 application ishereby incorporated fully by reference into the present application.

FIELD

The present disclosure generally relates to wireless communication, andmore particularly, to the transmission and reception of the systeminformation (SI) for the next generation wireless communicationnetworks.

BACKGROUND

The concept of on-demand System Information (SI) request has beenintroduced in the next generation wireless network (e.g., a 5^(th)generation (5G) new radio (NR) network). When a user equipment (UE)finds that a required SI message is not broadcast, the UE may perform anon-demand SI request procedure to ask the network to broadcast therequired System Information Blocks (SIBs) and/or the SI message(s).Another important feature in the next generation wireless network isnetwork sharing, which allows multiple public land mobile networks(PLMNs) to operate the same cell. Thus, there is a need for providing amethod for transmitting and receiving PLMN-specific system informationin a shared network.

SUMMARY

The present disclosure is directed to the transmission and reception ofthe system information for the next generation wireless communicationnetworks.

According to an aspect of the present disclosure, a method for receivingsystem information performed by a user equipment (UE) is provided. Themethod includes receiving a system information block type 1 (SIB1) froma cell. The SIB1 includes a first list. The number of entries in thefirst list ranges from one to the number of public land mobile networks(PLMNs) operating the cell. Each entry in the first list includes anindicator corresponding to a PLMN operating the cell and access controlinformation of the PLMN operating the cell.

According to another aspect of the present disclosure, a UE is provided.The UE includes one or more non-transitory computer-readable mediahaving computer-executable instructions embodied thereon and at leastone processor coupled to the one or more non-transitorycomputer-readable media. The at least one processor is configured toexecute the computer-executable instructions to receive a SIB1 from acell. The SIB1 includes a first list. The number of entries in the firstlist ranges from one to the number of public land mobile networks(PLMNs) operating the cell. Each entry in the first list includes anindicator corresponding to a PLMN operating the cell and access controlinformation of the PLMN operating the cell.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the example disclosure are best understood from the followingdetailed description when read with the accompanying figures. Variousfeatures are not drawn to scale, dimensions of various features may bearbitrarily increased or reduced for clarity of discussion.

FIG. 1 is a diagram illustrating the system information transmissionbetween a UE and a gNB, according to an example implementation of thepresent application.

FIG. 2 is a diagram illustrating a process of system information requestand response, according to an example implementation of the presentapplication.

FIG. 3 shows one format of an RRC system information request message,according to an example implementation of the present application.

FIG. 4 shows an example of a PLMN identity, according to an exampleimplementation of the present application.

FIG. 5 shows another format of an RRC system information requestmessage, according to an example implementation of the presentapplication.

FIG. 6 shows an example of a truncated PLMN identity, according to anexample implementation of the present application.

FIG. 7 shows one format of a SIB, according to an example implementationof the present application.

FIG. 8 shows another format of a SIB, according to an exampleimplementation of the present application.

FIG. 9 shows an example of different versions of the same systeminformation block, according to an example implementation of the presentapplication.

FIG. 10 shows another format of a SIB, according to an exampleimplementation of the present application.

FIG. 11 shows another format of a SIB, according to an exampleimplementation of the present application.

FIG. 12 shows another format of a SIB, according to an exampleimplementation of the present application.

FIG. 13 shows one format of PLMN-specific cell access relatedinformation, according to an example implementation of the presentapplication.

FIG. 14 shows a medium access control (MAC) control element (CE)including a field “D” for indicating the broadcast delay time, accordingto an example implementation of the present application.

FIG. 15 shows a MAC CE including a field “B” for indicating thebroadcast monitoring duration, according to an example implementation ofthe present application.

FIG. 16 shows a MAC CE including a field “UL Grant” for indicating theuplink resources for a UE, according to an example implementation of thepresent application.

FIG. 17 shows a MAC CE including a field “DL Grant” for indicating thedownlink resources for a UE, according to an example implementation ofthe present application.

FIG. 18 shows a MAC CE including fields “D”, “B”, “UL Grant”, and “DLGrant”, according to an example implementation of the presentapplication.

FIG. 19 shows a MAC CE including fields “D”, “B”, “UL Grant”, “DLGrant”, and “A/N” for indicating acknowledgment, according to an exampleimplementation of the present application.

FIG. 20 shows a MAC CE including fields “D”, “B”, “UL Grant”, “DLGrant”, and the UE contention resolution identity, according to anexample implementation of the present application.

FIG. 21 is a flowchart for a method of wireless communications performedby a UE, according to an example implementation of the presentapplication.

FIG. 22 is a sequence diagram illustrating a process of systeminformation request and response, according to an example implementationof the present application.

FIG. 23 illustrates a block diagram of a node for wirelesscommunication, in accordance with various aspects of the presentapplication.

DETAILED DESCRIPTION

The following description contains specific information pertaining toexample implementations in the present disclosure. The drawings in thepresent disclosure and their accompanying detailed description aredirected to merely example implementations. However, the presentdisclosure is not limited to merely these example implementations. Othervariations and implementations of the present disclosure will occur tothose skilled in the art. Unless noted otherwise, like or correspondingelements among the figures may be indicated by like or correspondingreference numerals. Moreover, the drawings and illustrations in thepresent disclosure are generally not to scale, and are not intended tocorrespond to actual relative dimensions.

For the purpose of consistency and ease of understanding, like featuresare identified (although, in some examples, not shown) by numerals inthe example figures. However, the features in different implementationsmay be differed in other respects, and thus shall not be narrowlyconfined to what is shown in the figures.

The description uses the phrases “in one implementation,” or “in someimplementations,” which may each refer to one or more of the same ordifferent implementations. The term “coupled” is defined as connected,whether directly or indirectly through intervening components, and isnot necessarily limited to physical connections. The term “comprising,”when utilized, means “including, but not necessarily limited to”; itspecifically indicates open-ended inclusion or membership in theso-described combination, group, series and the equivalent. Theexpression “at least one of A, B and C” or “at least one of thefollowing: A, B and C” means “only A, or only B, or only C, or anycombination of A, B and C.”

Additionally, for the purposes of explanation and non-limitation,specific details, such as functional entities, techniques, protocols,standard, and the like are set forth for providing an understanding ofthe described technology. In other examples, detailed description ofwell-known methods, technologies, system, architectures, and the likeare omitted so as not to obscure the description with unnecessarydetails.

Persons skilled in the art will immediately recognize that any networkfunction(s) or algorithm(s) described in the present disclosure may beimplemented by hardware, software or a combination of software andhardware. Described functions may correspond to modules may be software,hardware, firmware, or any combination thereof. The softwareimplementation may comprise computer executable instructions stored oncomputer readable medium such as memory or other type of storagedevices. For example, one or more microprocessors or general purposecomputers with communication processing capability may be programmedwith corresponding executable instructions and carry out the describednetwork function(s) or algorithm(s). The microprocessors or generalpurpose computers may be formed of applications specific integratedcircuitry (ASIC), programmable logic arrays, and/or using one or moredigital signal processor (DSPs). Although some of the exampleimplementations described in this specification are oriented to softwareinstalled and executing on computer hardware, nevertheless, alternativeexample implementations implemented as firmware or as hardware orcombination of hardware and software are well within the scope of thepresent disclosure.

The computer readable medium includes but is not limited to randomaccess memory (RAM), read only memory (ROM), erasable programmableread-only memory (EPROM), electrically erasable programmable read-onlymemory (EEPROM), flash memory, compact disc read-only memory (CD-ROM),magnetic cassettes, magnetic tape, magnetic disk storage, or any otherequivalent medium capable of storing computer-readable instructions.

A radio communication network architecture (e.g., a long term evolution(LTE) system, an LTE-Advanced (LTE-A) system, an LTE-Advanced Prosystem, or a 5G New Radio (NR) Radio Access Network) typically includesat least one base station, at least one user equipment (UE), and one ormore optional network elements that provide connection towards anetwork. The UE communicates with the network (e.g., a core network(CN), an evolved packet core (EPC) network, an Evolved UniversalTerrestrial Radio Access network (E-UTRAN), a 5G Core (5GC), or aninternet), through a radio access network (RAN) established by one ormore base stations.

It should be noted that, in the present application, a UE may include,but is not limited to, a mobile station, a mobile terminal or device, auser communication radio terminal. For example, a UE may be a portableradio equipment, which includes, but is not limited to, a mobile phone,a tablet, a wearable device, a sensor, a vehicle, or a personal digitalassistant (PDA) with wireless communication capability. The UE isconfigured to receive and transmit signals over an air interface to oneor more cells in a radio access network.

A base station may be configured to provide communication servicesaccording to at least one of the following radio access technologies(RATs): Worldwide Interoperability for Microwave Access (WiMAX), GlobalSystem for Mobile communications (GSM, often referred to as 2G), GSMEDGE radio access Network (GERAN), General Packet Radio Service (GRPS),Universal Mobile Telecommunication System (UMTS, often referred to as3G) based on basic wideband-code division multiple access (W-CDMA),high-speed packet access (HSPA), LTE, LTE-A, eLTE (evolved LTE, e.g.,LTE connected to 5GC), New Radio (NR, often referred to as 5G), and/orLTE-A Pro. However, the scope of the present application should not belimited to the above mentioned protocols.

A base station may include, but is not limited to, a node B (NB) as inthe UMTS, an evolved node B (eNB) as in the LTE or LTE-A, a radionetwork controller (RNC) as in the UMTS, a base station controller (BSC)as in the GSM/GERAN, a ng-eNB as in an E-UTRA base station in connectionwith the 5GC, a next generation node B (gNB) as in the 5G-RAN, and anyother apparatus capable of controlling radio communication and managingradio resources within a cell. The base station may connect to serve theone or more UEs through a radio interface to the network.

The base station is operable to provide radio coverage to a specificgeographical area using a plurality of cells forming the radio accessnetwork. The base station supports the operations of the cells. Eachcell is operable to provide services to at least one UE within its radiocoverage. More specifically, each cell (often referred to as a servingcell) provides services to serve one or more UEs within its radiocoverage (e.g., each cell schedules the downlink and optionally uplinkresources to at least one UE within its radio coverage for downlink andoptionally uplink packet transmissions). The base station cancommunicate with one or more UEs in the radio communication systemthrough the plurality of cells. A cell may allocate sidelink (SL)resources for supporting proximity service (ProSe) or Vehicle toEverything (V2X) service. Each cell may have overlapped coverage areaswith other cells.

As discussed above, the frame structure for NR is to support flexibleconfigurations for accommodating various next generation (e.g., 5G)communication requirements, such as enhanced mobile broadband (eMBB),massive machine type communication (mMTC), ultra reliable communicationand low latency communication (URLLC), while fulfilling highreliability, high data rate and low latency requirements. The orthogonalfrequency-division multiplexing (OFDM) technology as agreed in 3GPP mayserve as a baseline for NR waveform. The scalable OFDM numerology, suchas the adaptive sub-carrier spacing, the channel bandwidth, and theCyclic Prefix (CP) may also be used. Additionally, two coding schemesare considered for NR: (1) low-density parity-check (LDPC) code and (2)Polar Code. The coding scheme adaption may be configured based on thechannel conditions and/or the service applications.

Moreover, it is also considered that in a transmission time interval TXof a single NR frame, a downlink (DL) transmission data, a guard period,and an uplink (UL) transmission data should at least be included, wherethe respective portions of the DL transmission data, the guard period,the UL transmission data should also be configurable, for example, basedon the network dynamics of NR. In addition, sidelink resource may alsobe provided in an NR frame to support ProSe services or V2X services.

As described above, when a UE determines that a required SI message isnot broadcast by a base station (e.g., a gNB), the UE may perform anon-demand system information (SI) request procedure to ask the networkto broadcast the required SI message(s). In some implementations, theon-demand SI request procedure may include a Message 1 (MSG1) basedapproach and a Message 3 (MSG3) based approach.

In some of the present implementations, if the minimum SI includesinformation related to a Random Access (RA) preamble and/or a PhysicalRandom Access Channel (PRACH) occasion specific to each SIB or set ofSIBs (which the UE needs to acquire), the SI request may be indicatedusing an MSG1-based approach. For example, the RA preamble that the UEtransmits (e.g., during MSG1 transmission in the 4-step Random AccessChannel (RACH) procedure, or during MSGA transmission in the 2-step RACHprocedure) may correspond to the system information (e.g., SIB, SImessage) requested by the UE. For example, the PRACH occasion(s) wherethe UE transmits the RA preamble (e.g., during MSG1 transmission in the4-step RACH procedure, or during MSGA transmission in the 2-step RACHprocedure) may be associated with the system information (e.g., SIB, SImessage) requested by the UE. The UE may implicitly inform the basestation of the requested system information (e.g., SIB, SI message) viathe RA preamble and/or the PRACH occasion(s). The minimum SI may includethe Master Information Block (MIB) and the SIB1. In someimplementations, a Message 2 (MSG2) (e.g., random access response (RAR))may include a Random Access Preamble Index (RAPID). In oneimplementation, the MSG2 may not include fields such as Timing Advance(TA), UL grant and Temporary Cell Radio Network Temporary Identifier(C-RNTI). In some of the present implementations, the UE may consider anRACH procedure for an SI request to be successful when the UE receivesan MSG2 (e.g., RAR) that includes an RAPID corresponding to thetransmitted RA preamble (e.g., during MSG1 transmission in the 4-stepRACH procedure, or during MSGA transmission in the 2-step RACHprocedure). The medium access control (MAC) entity of the UE mayindicate, to the upper layers (e.g., RRC layer) of the UE, that itreceives an acknowledgement for the SI request. In some of the presentimplementations, the UE may consider an RACH procedure for the SIrequest to be successful when the UE receives an MSG2 (e.g., RAR) thatincludes the information related to the PRACH occasion(s) where the UEtransmits the RA preamble (e.g., during MSG1 transmission in the 4-stepRACH procedure, or during MSGA transmission in the 2-step RACHprocedure). The UE may receive the MSG2 (e.g., RAR) identified by anRA-RNTI that is associated with the PRACH occasion where the RA preambleis transmitted by the UE.

In one implementation, the SI request may be considered unsuccessfulwhen the UE does not receive an MSG2 (e.g., RAR) within an RAR window.In some of the present implementations, the UE may retransmit the RApreamble according to an NR RA power ramping when the SI request isconsidered to be unsuccessful. In one implementation, retransmission ofthe RA preamble may continue until the number of preamble transmissionsreaches a predetermined threshold. Thereafter, an RA problem may beindicated to the upper layer (e.g., RRC layer).

In some of the present implementations, if the minimum SI does notinclude information related to the RA preamble and/or the PRACH resource(or PRACH occasions) specific to each SIB or set of SIBs (which the UEneeds to acquire), an SI request may be sent using an MSG3-basedapproach. For example, the MSG3 transmitted by the UE may indicate therequested system information. The UE may determine whether theMSG3-based approach is successful or not based on a reception of anMSG4. In the MSG3-based approach for the SI request, the preamble(s)and/or the PRACH occasions may not be reserved in some aspects of thepresent implementations. Radio Resource Control (RRC) signaling may beused for the SI request in an MSG3-based approach. The RRC messageincluding the SI request may be called an RRC System Information Requestmessage (e.g., RRCSystemInfoRequest message). The RRC message includingthe SI request may be carried by Signaling Radio Bearer 0 (e.g., SRB0)from an RRC layer of the UE to a MAC layer of the UE. The SRB0 carryingthe RRC message including the SI request may be carried via the commoncontrol channel (CCCH), which is configured with transparent mode (TM)Radio Link Control (RLC) entity. For example, the MSG3 may include theCCCH service data unit (SDU), which may include an RRC message for theSI request (e.g., RRCSystemInfoRequest message).

In some of the present implementations, the UE may use a temporaryC-RNTI received in the MSG2 (e.g., RAR) for an MSG4 reception. Forexample, the UE may monitor the Physical Downlink Control Channel(PDCCH) transmission addressed to the temporary C-RNTI which the UEreceives in the MSG2 (e.g., RAR) to receive the MSG4. The MSG4 mayinclude a contention resolution MAC Control Element (CE). The UE maycheck the contention resolution MAC CE against the CCCH SDU thatincludes the SI request transmitted in the MSG3.

A System Information Block Type 1 (SIB1) may carry the schedulinginformation for the System Information (SI) messages. The schedulinginformation of an SI message may include the periodicity of the SImessage and what kinds of system information blocks (SIBs) may becarried by the SI message. Mapping of the SIBs to the SI messages may beflexibly configured by the scheduling information in the SIB1. However,each SIB may be contained only in a single SI message, and at most oncein the SI message. Only the SIBs that have the same schedulingrequirement (e.g., periodicity) may be mapped to the same SI message.Thus, the SIBs in the same SI message may be broadcast with the sameperiodicity. There may be multiple SI messages transmitted with the sameperiodicity. The SIB1 and all SI messages may be transmitted on theDownlink Shared Channel (DL-SCH). The SIBs carried by the SI messagesmay broadcast cell-specific system information.

In the next-generation cellular network, network sharing may become moreand more popular. For example, in LTE, at most six Public Land MobileNetworks (PLMNs) may share the same LTE evolved Node B(eNB). The LTESIB1 may broadcast at most six PLMN identities in the cell accessrelated information. The UEs that select a specific PLMN whose identityis broadcast by the LTE eNB may select and access the LTE cell. OtherUEs that select different PLMNs, but camp on the same cell, may sharethe same cell-specific system information. In New Radio (NR), in oneimplementation, up to twelve PLMN IDs may be broadcast in the minimum SIby an NR gNB. Each PLMN may set its own Tracking Area Code (TAC) andcell identity for a shared NR cell.

Additionally, several parameters in the system information may bePLMN-specific. For example, in NR, it is possible (but not limited) toset an SI area identity (ID), a tracking area code (TAC), a cellidentity (Cell ID), cell reservation indication and access controlparameters per PLMNs. Each PLMN identity (or indicator) may correspondto an SI area identity, a tracking area code, a cell identity, cellreservation indication and/or access control parameters. However, thetransport block (TB) size may be limited. The TB size may increase tocarry the PLMN-specific parameters in the system information. Thus, itis important to design the method of carrying the PLMN-specificparameters in the system information, as well as the method ofrequesting for and replying the system information. In NR, the gNB maytransmit the system information using three different approaches:broadcast periodically, on demand broadcast, and on demand unicast. Someof the present implementations describe a method of the PLMN-specificsystem information delivery, e.g., via periodic broadcasting, on demandbroadcasting, and/or on demand unicasting. Additionally, thePLMN-specific system information signaling structure are provided bysome of the present implementations.

FIG. 1 is a diagram 100 illustrating the system information transmissionbetween a UE and a gNB, according to an example implementation of thepresent application. As shown in diagram 100, in action 110, a UE 102may receive a SIB1 130 (e.g., as part of the minimum SI) from a cell,which may belong to one of the cells controlled by an NR gNB 104. Itshould be noted that the NR gNB 104 in the figures in the presentapplication is merely used as an example of a base station in thisimplementation. The method disclosed in the present application may alsobe applicable to other types of base stations. The SIB1 130 may includea first list 132. The number of entries in the first list 132 may rangefrom one to the number of PLMNs operating the cell. In the example shownin FIG. 1, the first list 132 includes twelve entries. Each entry in thefirst list 132 may include an indicator corresponding to a PLMNoperating the cell and access control information of the PLMN operatingthe cell.

In one implementation, the indicator in the first list 132 may be in theform of an index, a bitmap, an integer, or other appropriate formatscapable of indicating a particular PLMN. For example, if there are 7PLMNs operating a cell, a 3-bit index, a 7-bit bitmap, or an integer maybe used to indicate a particular PLMN. For the 3-bit index approach,“000” may indicate the first entry in the first list 132, “001” mayindicate the second entry in the first list 132, “010” may indicate thethird entry in the first list 132, and so on. For the 7-bit bitmapapproach, “0000001” may indicate the first entry in the first list 132,“0000010” may indicate the second entry, “0000100” may indicate thethird entry, and so on. For the integer approach, “1” may indicate thefirst entry in the first list 132, “2” may indicate the second entry inthe first list 132, “3” may indicate the third entry in the first list132, and so on.

In one implementation, the indicator in the first list 132 may be acomplete PLMN identity (ID) or a truncated PLMN identity. The completePLMN ID may include a Mobile Country Code (MCC) and a Mobile NetworkCode (MNC). The truncated PLMN ID may include a portion of the completePLMN ID. In one implementation, the MCC may include 3 decimal digits andthe MNC may also include 3 decimal digits. The complete PLMN ID mayinclude 6 digits, and the truncated PLMN ID may include an MCC fewerthan 3 digits and/or an MNC fewer than 3 digits. It is possible that thetruncated PLMN ID may not have an MCC and only include an MNC having 3digits or less. For example, in some aspects of the presentimplementations, the MCC field may be optional.

As shown in FIG. 1, the right column in the first list 132 may be theaccess control information corresponding to the PLMN shown in the leftcolumn in the first list 132. The access control information of a PLMNmay include one or more access control parameters. In oneimplementation, one of the access control parameters may indicate apossibility value that a UE may be connected to the cell owned by thePLMN. The possibility value may represent the success probability of theaccess attempt made by the UE to be allowed by the cell. In oneimplementation, one of the access control parameters may indicate a timevalue during which the UE may be barred from access to the cell. Uponreceiving the SIB1 130, the UE 102 may recognize the access controlinformation of each PLMN operating the cell belonging to the NR gNB 104.

FIG. 2 is a diagram 200 illustrating transmission of system informationfrom a gNB to a UE, according to an example implementation of thepresent application. The diagram 200 may include actions 210 and 212. Inaction 210, the UE 102 may transmit an RRC message to request systeminformation (e.g., RRCSystemInfoRequest message) from the NR gNB 104.The RRCSystemInfoRequest message may include the PLMN informationassociated with the UE 102. In action 212, upon receiving theRRCSystemInfoRequest message including the PLMN information of the UE102, the NR gNB 104 may transmit the PLMN-specific system information(e.g., system information block(s), system information message (SImessage), etc.) requested by the UE 102. For example, if the PLMNinformation of the UE 102 transmitted in action 210 indicates that theUE 102 registers to PLMN#3, the system information transmitted in action212 may be system information specific to the PLMN#3. In action 212, theNR gNB 104 may transmit the PLMN-specific system information to the UE102 via broadcast or through dedicated downlink resources (e.g.,unicast). In one implementation, the RRCSystemInfoRequest message may besent from the UE 102 to the NR gNB 104. The RRCSystemInfoRequest messagemay be carried via the common control channel (CCCH) (e.g., from the RLCentity of the UE 102 to the MAC entity of the UE 102, from the MACentity of the NR gNB 104 to the RLC entity of the NR gNB 104), which maybe configured with transparent mode (TM) RLC entity, with the signalingradio bearer of SRB0. For example, the RRC Packet Data Unit (PDU) thatincludes the RRCSystemInfoRequest message may be mapped to an RLCService Data Unit (SDU) for transmission. In some of the presentimplementations, the CCCH may be a logical channel offered by the MACentities of the UE 102 and the NR gNB 104.

There may be several approaches for the UE 102 to indicate its PLMNinformation to the NR gNB 104 in an RRC message (e.g.,RRCSystemInfoRequest message):

Case #1-1: The UE 102 may include its complete PLMN ID in the RRCmessage (e.g., RRCSystemInfoRequest message). FIG. 3 shows one format ofan RRC system information request message, according to an exampleimplementation of the present application. Abstract Syntax Notation One(ASN.1) may be used to describe the data structure of variousimplementations of a message in the present application. As shown inFIG. 3, a data structure 300 of the RRCSystemInfoRequest message mayinclude the complete PLMN ID or the truncated PLMN ID.

FIG. 4 shows an example of a PLMN identity, according to an exampleimplementation of the present application. A data structure 400 of acomplete PLMN ID may include optional X MCC digits and Y MNC digits. Itshould be noted that X and Y may be zero or positive integer(s). Asshown in FIG. 4, the X MCC digits may be optionally present in thecomplete PLMN ID. In one implementation, the X MCC digits may be presentin the complete PLMN ID when the corresponding PLMN is the first entryin a list of PLMNs (e.g. the first list 132 shown in FIG. 1). In suchimplementation, the X MCC digits may be absent in the complete PLMN IDwhen the corresponding PLMN is not the first entry in the list of PLMNs.

Case #1-2: the UE 102 may include its truncated PLMN ID in the RRCmessage (e.g., RRCSystemInfoRequest message). FIG. 5 shows anotherformat of an RRC system information request message, according to anexample implementation of the present application. As shown in FIG. 5, adata structure 500 of the RRCSystemInfoRequest message may include thetruncated PLMN ID.

In one implementation, the UE 102 may include either Y1 MNC digits (Y1may be less than or equal to Y) or X1 MCC digits (X1 may be less than orequal to X) as its truncated PLMN ID in the RRC message (e.g.,RRCSystemInfoRequest message). In another implementation, the UE mayinclude combination of Y1 MNC digits and X1 MCC digits as its truncatedPLMN ID in the RRC message (e.g., RRCSystemInfoRequest message). Thevalues of X1 and Y1 may be preconfigured. It should be noted that X1 andY1 may be zero or positive integer(s).

FIG. 6 shows an example of a truncated PLMN identity, according to anexample implementation of the present application. A data structure 600of a truncated PLMN ID may include optional X1 truncated MCC digits andY truncated MNC digits.

Case #1-3: The UE may include an indicator of its PLMN ID in the RRCmessage (e.g., RRCSystemInfoRequest message).

Case #1-3-1: The indicator may be a Z1-bit index to represent the numberof PLMNs shared by the NR gNB 104, where Z1 may be a positive integer.For example, if the NR gNB supports maximum eight PLMNs, a three-bitindex may be used to represent the PLMN information. In oneimplementation, ‘000’ may represent the first entry of a PLMN listbroadcast by the NR gNB 104. The increasing index may correspond to theascending order of PLMNs in the PLMN list. In another implementation,‘000’ may represent the last entry of the PLMN list broadcast by the NRgNB 104.

Case #1-3-2: The indicator may be a Z2-bit bitmap, where Z2 may be apositive integer. Each bit in the bitmap may correspond to one PLMNprovided by the NR gNB 104. For example, if the NR gNB 104 supportsmaximum twelve PLMNs sharing the network, Z2 may be twelve. In oneimplementation, the most significant bit of the bitmap may represent thefirst entry of a PLMN list broadcast by the NR gNB 104. The bit afterthe most significant bit of the bitmap may represent the second entry ofthe PLMN list broadcast by the NR gNB 104, and so on. In oneimplementation, the least significant bit of the bitmap may representthe last entry of the PLMN list broadcast by the NR gNB 104. In oneimplementation, the least significant bit of the bitmap may representthe first entry of the PLMN list broadcast by the NR gNB 104. The bitbefore the least significant bit of the bitmap may represent the secondentry of the PLMN list broadcast by the NR gNB 104, and so on. In oneimplementation, the most significant bit of the bitmap may represent thelast entry of a PLMN list broadcast by the NR gNB 104.

Case #1-3-3: The indicator may be an integer which may uniquely indicatea selected PLMN sharing the NR gNB 104. In one implementation, theinteger being set as 1 may indicate that the first PLMN is selected fromthe PLMN list information in the minimum SI (e.g., SIB1), and theinteger being set as 2 may indicate that the second PLMN is selectedfrom the PLMN list information in the minimum SI (e.g., SIB1). In thisimplementation, the maximum value of the integer may be the maximumnumber of the PLMNs sharing the NR gNB 104. In another implementation,the integer being set as 0 may indicate that the first PLMN is selectedfrom the PLMN list information in the minimum SI (e.g., SIB1), and theinteger being set as 1 may indicate that the second PLMN is selectedfrom the PLMN list information in the minimum SI (e.g., SIB1). In thisother implementation, the maximum value of the integer may be themaximum number of the PLMNs sharing the NR gNB 104 minus 1.

In one implementation, if the UE 102 does not include any indicator ofPLMN information (e.g., any indicator disclosed in Case #1-3, thecomplete PLMN ID in Case #1-1, or the truncated PLMN ID in Case #1-2) inthe RRC message (e.g., RRCSystemInfoRequest message), the NR gNB 104 maydetermine that every PLMN-specific system information has beenrequested. In another implementation, the NR gNB 104 may determine thatno PLMN-specific system information is requested if the UE 102 does notinclude any indicator of PLMN information.

Case #1-4: The system information messages may be implicitly mapped tothe corresponding PLMNs. In this case, the fact that the UE 102 requeststhe system information messages may implicitly represent that the UE 102provides its PLMN information to the NR gNB 104. Table 1 below shows anexample relationship between a system information message andPLMN-specific system information it carries. For example, the systeminformation message #1 may provide at least the system information forPLMN#A. In one implementation, the UE 102 may implicitly or indirectlyprovide its PLMN information (e.g., PLMN#A) by requesting the systeminformation (SI) message #1, based on the relationship shown in Table 1below. In one implementation, the order of the SI messages may beimplicitly mapped to the PLMN entry order of the PLMN ID list, which maybe broadcast by the NR gNB 104.

TABLE 1 SI messages and corresponding PLMN information SystemInformation Message System Information SI message #1 System informationfor PLMN#A SI message #2 System information for PLMN#A SI message #3System information for PLMN#B

Once the NR gNB 104 receives the RRCSystemInfoRequest message, the NRgNB 104 may reply to the UE 102 with system information (e.g., systeminformation message, system information blocks). If the UE 102 providesits PLMN information in the RRC message (e.g., RRCSystemInfoRequestmessage), the NR gNB 104 may reply to the UE 102 with the systeminformation corresponding to the provided PLMN information.

Case #2-1: If the requested SI message includes system informationcorresponding to several different PLMNs, the NR gNB 104 may unicast orbroadcast the system information related to the PLMN information in theRRC message (e.g., RRCSystemInfoRequest message) provided by the UE 102.

One SI message may include at least one system information block withthe same periodicity, and each system information block may carry systeminformation. Within a system information block, some system informationmay be PLMN-specific and some may not be.

FIG. 7 shows one format of a SIB, according to an example implementationof the present application. For example, a data structure 700 of thesystem information block may contain cell-specific information (e.g.,Cell-specific-IE) and PLMN-specific information (e.g.,PLMN#1-specific-IE for PLMN#1 system information). PLMN#1-specific-IEand PLMN#2-specific-IE may have different system information for PLMN#1and PLMN#2, respectively, such as different values for the same systeminformation category, or different system information categories.PLMN#1-Specific-Info and PLMN#2-Specific-Info may further include thePLMN identities of PLMN#1 and PLMN#2, respectively. The format of thePLMN identity may be a complete PLMN ID, a truncated PLMN ID, a bitmap,an index, an integer, etc. The cell-specific information (e.g.,Cell-specific-IE) may be optionally present in the data structure 700 ofthe system information block. The PLMN-specific information may bepresent in the data structure 700 of the system information block if theNR gNB receives the PLMN information in the RRC message (e.g.,RRCSystemInfoRequest message).

FIG. 8 shows another format of a SIB, according to an exampleimplementation of the present application. A data structure 800 of thesystem information block may include cell-specific information (e.g.,Cell-specific-IE) and PLMN-specific information (e.g.,PLMN-specific-IE). In one implementation, the PLMN-specific-IE may be adata structure, such as a list. Each entry in the list may involve aPLMN identity and its corresponding PLMN-specific information. Theformat of the PLMN identity may be a complete PLMN ID, a truncated PLMNID, a bitmap, an index, an integer, etc. In one implementation, thePLMN-specific information may be access control information of a PLMNcorresponding to the PLMN identity. In the example shown in FIG. 8, itis possible that all PLMNs use the same system information category(e.g., PLMN-INFO) having different values. The access controlinformation may be one kind of system information category. In someimplementations, PLMN-INFO may represent different system informationcategories for different PLMNs.

In this scenario, the NR gNB 104 may transmit at least the PLMN-specificsystem information of a PLMN that is provided by the UE 102 in the RRCmessage (e.g., RRCSystemInfoRequest message). The PLMN-specific systeminformation may be included in some system information blocks which areinformed by the SI request message (e.g., RRCSystemInfoRequest message).For example, if the RRC message (e.g., RRCSystemInfoRequest message)does not include the PLMN information, the NR gNB 104 may transmit thecell-specific information only (e.g., the Cell-specific-IE in FIG. 7 andFIG. 8) and/or all of the PLMN-specific information. For example, if theRRC message (e.g., RRCSystemInfoRequest message) includes the PLMNinformation of the UE 102, the NR gNB 104 may transmit, at least, thesystem information specific to the PLMN information of the UE 102. Thus,the cell-specific system information may be optionally transmitteddepending on the information in the RRC message (e.g.,RRCSystemInfoRequest message). The PLMN-specific information (e.g., thePLMN#1-specific-IE and the PLMN#2-specific-IE in FIG. 7, thePLMN-specific-IE in FIG. 8) may be transmitted when the PLMN informationis included in the RRC message (e.g., RRCSystemInfoRequest message).

Case #2-2: If the requested SI message includes several systeminformation blocks and each system information block contains systeminformation for a specific PLMN, the NR gNB 104 may transmit only thesystem information blocks for the corresponding PLMN provided by the UE102 in the RRC message (e.g., RRCSystemInfoRequest message) to the UE102.

One SI message may include at least one system information block withthe same periodicity, and each system information block may carry thesystem information. In one implementation, the system information blockmay have several versions and each version may include systeminformation for a specific PLMN. FIG. 9 shows an example of differentversions of the same system information block, according to an exampleimplementation of the present application. For example, an SI messagemay include a SIB#A, and the SIB#A may have twelve versions. A datastructure 900 may include different versions of the SIB#A. TheSIB#A-version#1 may include the PLMN#1-specific SIB#A, and theSIB#A-version#2 may include the PLMN#2-specific SLB#A, etc., as shown inFIG. 9. If the UE 102, that selects PLMN#1, requests the SI message forSIB#A, the NR gNB 104 may transmit the SIB#A-version#1 rather than otherversions of the SIB#A. Thus, the SIB#A with different versions may betransmitted by different SI delivery approaches. If the UE 102 includesits PLMN information in the RRCSystemInfoRequest message and asks forSIB#A, the NR gNB 104 may transmit a version of the SIB#A thatcorresponds to the PLMN information of the UE 102. Thus, other versionsof the SIB#A may not be transmitted. In one implementation, the same SIBnumber with different versions may also be indicated by different SIBnumberings. For example, SIB#A-version#1 may be SIB#A1, SIB#A-version#2may be SIB#A2, and so on. SIB#A1 and SIB#A2 may include systeminformation of different PLMNs.

Case #2-3: If the requested SI message has different types and each typecorresponds to specific PLMNs, the NR gNB 104 may transmit the systeminformation blocks in the requested SI message with the same typecorresponding to the PLMN information provided by the UE 102 in the RRCmessage (e.g., RRCSystemInfoRequest message).

One SI message may include at least one system information block withthe same periodicity, and each system information block may carry thesystem information. In one implementation, one SI message may haveseveral types and each type of the SI message may carry systeminformation blocks for a particular PLMN. Thus, when the UE 102indicates an SI message(s) and its PLMN information in the RRC message(e.g., RRCSystemInfoRequest message), the NR gNB 104 may transmit therequested SI message(s) with the type for the specific PLMN.

FIG. 10 shows another format of a SIB, according to an exampleimplementation of the present application. A data structure 1000 of theSIB1 130 may include scheduling information of system information (e.g.,SI-SchedulingInfo in FIG. 10). The SIB1 130 may include the schedulinginformation of the system information under certain conditions, whileunder other circumstances, the SIB1 130 may not include the schedulinginformation of the system information. The scheduling information of thesystem information may be optionally present in the SIB1 130. TheSI-SchedulingInfo may include a list of scheduling info of each SImessage (e.g., SchedulingInfo in FIG. 10). The size of the list ofscheduling info may range from 1 to the maximum number of the SImessages. The SchedulingInfo may include a broadcast status (e.g.,si-BroadcastStatus in FIG. 10). The si-BroadcastStatus may indicatewhether the SI message and the corresponding SIBs are currentlybroadcast or not. If they are broadcast, they may be broadcastperiodically or broadcast on demand. In one implementation, with thePLMN identity information in the scheduling information of the SImessage, the UE may further infer that the SI message is on demandbasis. In one implementation, the si-BroadcastStatus may be ENUMERATED{broadcast, onDemand}, to let the UE know whether the SI message iscurrently (periodically) broadcast or it should be requested on demand.

In one implementation, the scheduling information (e.g., SchedulingInfoin FIG. 10) in the data structure 1000 may further include PLMNinformation (e.g., si-plmn) for an SI message to let the UE 102 knowwhat type of the SI message is currently broadcast/unicast. The PLMNinformation (e.g., si-plmn) may be (but not limited to) a PLMN identityor any representatives/short codes/index/integer of the PLMN identity.

FIG. 11 shows another format of a SIB, according to an exampleimplementation of the present application. In one implementation, thescheduling information of the SI message(s) may be grouped into twocategories: PLMN-specific and cell-specific, as shown in FIG. 11. A datastructure 1100 of the SIB1 130 may include PLMN-specific schedulinginformation and cell-specific scheduling information. Each PLMN may haveits own scheduling information of the SI message(s) (e.g.,SI-SchedulingInfo). A PLMN-specific list of SI-SchedulingInfo (e.g.,PLMN-SI-SchedulingInfoList in FIG. 11) may be adopted in the SIB1 130.The size of the PLMN-specific list may range from 1 to the maximumnumber of PLMNs operating the cell. The PLMN-specific schedulinginformation may be optionally present in the SIB1 130. In somecircumstances (e.g., the NR gNB 104 does not receive any RRC message(e.g., SI request message) including PLMN information), the NR gNB 104may not broadcast the PLMN-specific scheduling information in the SIB1130, while in other circumstances, the NR gNB 104 may broadcast thePLMN-specific scheduling information in the SIB1 130. In someimplementations, if the scheduling information of the system information(e.g., SI-SchedulingInfo) in the PLMN-specific scheduling information isabsent, the UE 102 may follow the stored, preconfigured or defaultscheduling information of the system information for the correspondingPLMN. The UE 102 may read only the SI-SchedulingInfo marked with thesame PLMN the UE selects. As such, all of the following information inthe SI-SchedulingInfo may be PLMN-specific to the UE 102 and UE 102 maynot need to check the PLMN information for the subsequent systeminformation. Each PLMN may be free to implement its own systeminformation. After reading the PLMN-specific scheduling information ofthe SI message(s), the UE 102 may find the system information that isspecific to the PLMN the UE selects. The cell-specific schedulinginformation of the SI message(s) may be generally applied to all UEscamped on the cell. The cell-specific scheduling information of the SImessage(s) may be absent in the SIB1 130 under some conditions. If theUE 102 does not receive the cell-specific scheduling information of theSI message(s), the UE 102 may apply the stored, preconfigured or defaultcell-specific scheduling information of the SI message(s).

For example, the PLMN-specific scheduling information of the SImessage(s) may schedule PLMN-specific system information (e.g., accesscontrol parameters). The cell-specific scheduling information of the SImessage(s) may schedule the system information carrying thecell-specific configuration for the serving cell. In one implementation,the data structure 1100 may include PLMN-specific access controlinformation in addition to (or instead of) the PLMN-specific schedulinginformation. For example, the list of PLMN-specific schedulinginformation shown in FIG. 11 may be a list of PLMN-specific accesscontrol information or access control parameters. Each entry in the listof PLMN-specific access control information may include a PLMN identity(the format of the PLMN identity may be an indicator, an index, aninteger, a bitmap, etc.) and its corresponding access controlinformation.

Case #3-1: Each PLMN may define its cell identity and tracking area codefor the cell. Thus, the cell may be tagged by a unique combination ofthe PLMN identity, the cell identity and the tracking area code. FIG. 12shows another format of a SIB, according to an example implementation ofthe present application. In one implementation, the system information(e.g., the SIB1) may broadcast a list of cell unique identities (e.g.,cellUniqueId), as shown in FIG. 12. The maximum number of entries in thelist may be the maximum number of PLMNs sharing the cell (e.g., 12 inNR). In one implementation, the number of entries in the list may rangefrom one to the number of PLMNs operating the cell. A data structure1200 of the SIB1 may include a CellUniqueId IE, which may include a cellglobal identity (e.g., CellGlobalIdNR) and a tracking area code. Thecell global identity may include a PLMN identity and a cell identity.Upon reading the cell unique identity information in the systeminformation, the UE 102 may know the PLMNs sharing the cell and the cellidentity and/or tracking area code assigned by the PLMN to the cell.

Case #3-2: Each PLMN may have its own cell access related informationfor a cell. FIG. 13 shows one format of PLMN-specific cell accessrelated information, according to an example implementation of thepresent application. The concept of the cellUniqueId may be included inthe cell access related information (e.g., cellAccessRelatedInfo IE inFIG. 13). Generally, the list of PLMN-specific cell access relatedinformation may be required in the system information. For example, theNR gNB 104 may broadcast or unicast the list of PLMN-specific cellaccess related information in the system information (e.g., SIB1). Foreach cell unique identity, there may be the corresponding cell accessrelated information. The cell access related information may be (but notlimited to) closed subscriber group (CSG) information, cell reservationinformation for operator usage, access control information, etc.

Case #3-3: Each PLMN may have its own NR inter-frequency cellre-selection information. Such information (e.g., PLMN-specific NRinter-frequency cell re-selection information) may be included in thesystem information (e.g., the SIB2, the SIB4). In one implementation,the system information block may include cell-specific and PLMN-specificinformation (in which case, the Case #2-1 may be applied). In oneimplementation, each SIB may have different versions corresponding todifferent PLMNs, as illustrated in the Case #2-2. In one implementation,the PLMN-specific NR inter-frequency cell re-selection information maybe a per-PLMN list structure of information elements (e.g., common cellreselection information, inter-frequency black cell list,inter-frequency carrier frequency list, inter-frequency neighboring celllist) similar to a data structure 1300 shown in FIG. 13.

Case #3-4: Each PLMN may have its own inter-RAT cell re-selectioninformation. Such information (e.g., PLMN-specific inter-RAT cellre-selection information) may be included in the system information(e.g., the SIB2, the SIB5). In one implementation, the systeminformation block may include cell-specific and PLMN-specificinformation (in which case, the Case #2-1 may be applied). In oneimplementation, each SIB may have different versions corresponding todifferent PLMNs, as illustrated in the Case #2-2. In one implementation,the PLMN-specific inter-RAT cell re-selection information may be aper-PLMN list structure of information elements (e.g., cell reselectioninformation common, cell reselection serving frequency information,information about E-UTRA frequencies and E-UTRAs neighbouring cells),similar to the data structure 1300 shown in FIG. 13.

Case #3-5: The access control parameters broadcast/unicast by the NR gNB104 may be cell-specific and/or PLMN-specific. If the access controlparameters are cell-specific, they may be referred as a common part ofthe access control information to access the NR gNB 104. If the accesscontrol parameters are PLMN-specific, they may be regarded as adifferent part of the access control information which may be configuredand customized by the PLMN. The cell-specific and PLMN-specific accesscontrol parameters may be carried in the SIB1, the SIB2, or other systeminformation blocks. The signaling structure in each system informationblock may utilize the implementations proposed in this disclosure todifferentiate between the common part (e.g., cell-specific) and thedifferent part (e.g., PLMN-specific) of the access control information.The UE 102 may apply the cell-specific access control parameters uponreceiving the cell-specific access control parameters in the systeminformation (e.g., SIB1). The UE 102 may apply the PLMN-specific accesscontrol parameters upon receiving the PLMN-specific access controlparameters in the system information (e.g., SIB1) or in the dedicatedsignaling (e.g., an RRC message). The UE 102 may apply both thecell-specific access control parameters and the PLMN-specific accesscontrol parameters upon receiving them in the system information. Insome implementations, the UE may apply the PLMN-specific access controlparameters if the parameters in the cell-specific access controlparameters and PLMN-specific access control parameters have a conflict.

Case #3-5-1: The NR gNB 104 may mandatorily broadcast the cell-specificaccess control parameters, which may be applied across multiple PLMNs.The cell-specific access control parameters may be carried in theminimum SI (e.g., the MIB and the SIB1). The PLMN-specific accesscontrol parameters may be broadcast/unicast by the NR gNB 104 on demand.In one implementation, both the cell-specific and the PLMN-specificaccess control parameters may be in the SIB1. In another implementation,both the cell-specific and the PLMN-specific access control parametersmay belong to another SI. If the cell-specific system information andthe PLMN-specific system information are mapped to different SImessages, it is possible that they may be transmitted with differentperiodicities by the NR gNB 104. It should be noted that if the UE 102does not provide the PLMN information during the system informationrequest, the NR gNB 104 may, by default, treat the request as beingsubject to the cell-specific SI.

Case #3-5-2: If the UE 102 passes the access control check following thecell-specific access control parameters, the UE 102 may further send, tothe NR gNB 104, the RRC message (e.g., RRCSystemInfoRequest message),which may include the PLMN information of the UE 102, to ask forPLMN-specific access control parameters.

Case #3-5-3: If the UE 102 is barred due to the access control checkfollowing the cell-specific access control parameters, the UE 102 maynot ask for PLMN-specific access control parameters.

Case #3-5-4: If the UE 102 is barred due to the access control checkfollowing the PLMN-specific access control parameters, the UE 102 maynot request any other PLMN-specific access control parameters.

There may be various implementations regarding how the NR gNB 104transmits the system information based on the RRC message (e.g.,RRCSystemInfoRequest message). The RRC message (e.g.,RRCSystemInfoRequest message) generated in the RRC layer of the UE 102may be transmitted to the NR gNB 104 via an MSG3 (in an RACH procedure)in the MAC layer of the UE 102. The RRC layer of the UE 102 may make theRRC PDU including the RRCSystemInfoRequest message and transmit it viaSRB0 carried by CCCH to the MAC entity of the UE 102. The MAC entity ofthe UE 102 may receive the CCCH SDU including the RRC PDU including theRRCSystemInfoRequest message. The MAC entity of the UE 102 may transmitthe MSG3 including the CCCH SDU. For the MAC layer activity, action 210shown in FIG. 2 may be referred to as transmission of the MSG3 by the UE102, where the MSG3 may include the RRCSystemInfoRequest message as aCCCH SDU.

Case #4-1: If the MSG3 does not include any UE-specific information(e.g., UE ID) or the RNTI (e.g., (temporary) C-RNTI, I-RNTI, SI-RNTI)addressed to the UE 102's Medium Access Control (MAC) entity, the NR gNB104 may transmit the system information via broadcast. If the NR gNB 104successfully receives and decodes the MSG3, the NR gNB 104 may replywith a MAC CE including acknowledgement and broadcasts the requestedsystem information. If the NR gNB 104 fails to receive and decode theMSG3, the NR gNB 104 may reply with a MAC CE including negativeacknowledgement (e.g., NACK).

Case #4-2: If the MSG3 includes the UE-specific information (e.g., UEID) and/or the RNTI (e.g., (temporary) C-RNTI, I-RNTI, SI-RNTI)addressed to the UE 102's MAC entity, the NR gNB 104 may transmit thesystem information either via broadcasting or via unicasting. It shouldbe noted that the UE 102 may receive the value of the RNTI (e.g.,(temporary) C-RNTI, I-RNTI, SI-RNTI) in a random access responsemessage. It is possible that the UE may receive the Physical DownlinkControl Channel (PDCCH) addressed to the RNTI (e.g., (temporary) C-RNTI,SI-RNTI).

Case #4-2-1: If the NR gNB 104 successfully receives and decodes theMSG3, the NR gNB 104 may reply with a MAC CE including acknowledgement,and broadcast/unicast the requested system information. The UE 102 maymonitor the PDCCH transmission addressed to the RNTI (e.g., (temporary)C-RNTI, I-RNTI, SI-RNTI) that the UE 102 transmits during the MSG3transmission, or the UE 102 receives in the random access response, toreceive the MAC CE including acknowledgement and/or unicast/broadcastsystem information. The PDCCH resources where the UE receives theunicast SI may be indicated in the MAC CE that includes theacknowledgement.

Case #4-2-2: If the NR gNB 104 fails to decode the MSG3, the NR gNB 104may reply with a MAC CE that includes negative acknowledgement (e.g.,NACK), and broadcast the requested system information.

In one implementation, the RRC message (e.g., RRCSystemInfoRequestmessage) transmitted by the UE 102 may include information related to atimer. In one implementation, the timer may be preconfigured to the UE102, broadcast in the system information by the NR gNB 104, ortransmitted in a dedicated signaling (e.g., RRC message) by the NR gNB104 to the UE 102. The UE 102 may start the timer after receiving theMAC CE with positive acknowledgement.

Case #5-1: The UE 102 may expect the requested system information istransmitted by the NR gNB 104 before the timer expires. Thus, the UE 102may not send the RRC message (e.g., RRCSystemInfoRequest message) to askfor the same system information (e.g., SI message, SIB) until the timerexpires. In one implementation, no preamble is retransmitted until thetimer expires. The UE 102 may send, to the NR gNB 104, the RRC message(e.g., RRCSystemInfoRequest message) or a preamble corresponding to theSI request message after the timer expires. If the UE 102 receives theSI message corresponding to the sent preamble or RRC message (e.g.,RRCSystemInfoRequest message), the UE 102 may stop the timer. The UE 102may send, to the NR gNB 104, the RRC message (e.g., RRCSystemInfoRequestmessage) or a preamble corresponding to the SI request message after thetimer is stopped.

Case #5-2: If the requested system information (e.g., SI message, SIB)includes a cell-specific part and a PLMN-specific part, at least thesystem information the UE 102 requests may continue to be broadcast bythe NR gNB 104 before the timer expires.

In one implementation, the timer may be preconfigured by the network(e.g., broadcast in SI or via dedicated signaling). The UE 102 may startthe timer after receiving the MAC CE and/or Downlink Control Information(DCI) with positive acknowledgement. The UE 102 may not be allowed toperform a new SI request procedure (e.g., transmit anotherRRCSystemInfoRequest message) again before the timer expires.

In one implementation, when the requested SI message(s) or SIB(s)includes PLMN-specific information (e.g., the SI for PLMN#1 and the SIfor PLMN#2), the NR gNB 104 may take turns to broadcast the requested SImessage(s) or SIB(s) in different system information periodicities or inthe same system information periodicity. For example, in the first SIperiod (or modification period or SI window), the NR gNB 104 maybroadcast the PLMN#1-specific system information in a requested SImessage or SIB. In the second SI period (or modification period or SIwindow), the NR gNB 104 may broadcast the PLMN#2-specific systeminformation in a requested SI message or SIB, and so on.

In one implementation, the NR gNB 104 may send a MAC CE including afield “D” to indicate a broadcast delay time within an MSG4 to the UE102. FIG. 14 shows a MAC CE 1400 including a field “D” 140 forindicating the broadcast delay time, according to an exampleimplementation of the present application. In one implementation, thebroadcast delay time may be indicated by DCI. The broadcast delay timemay indicate to the UE 102 when the requested SI (e.g., SIB(s) and SImessage(s)) begins to be broadcast. In one implementation, uponreceiving the broadcast delay time, the UE 102 may wait for (at least)the broadcast delay time and start the system information acquisitionfrom the start of the next modification period. In one implementation,the UE 102 may monitor the start of the modification period within thebroadcast delay time to start the system information acquisition. In oneimplementation, regardless of the modification period, the UE 102 mayassume that the required SIB(s) or SI message(s) begin to be broadcastafter broadcast delay time counting from an MSG4 is received. Forexample, if the broadcast delay time is X and the UE 102 receives theMSG4 at Y time point, and if the contention resolution of the UE 102 issuccessful, then the UE 102 may start to read the requested SIB(s) or SImessage(s) at Y+X time point. In one implementation, a new value of alogical channel ID (LCID) may be needed to represent the MAC CE 1400including the field “D” 140. The LCID may be placed in the MAC subheaderassociated to the MAC CE 1400. In the example shown in FIG. 14, thefield “D” 140 may be an octet having a bit width of 8. In otherimplementations, the bit number of the broadcast delay time may not belimited to a fixed bit width (e.g., the bit width may be extended orshrunk). In one implementation, if the UE 102 receives a MAC CE with thebroadcast delay time, the UE 102 may regard it as a positiveacknowledgement. If the UE 102 does not receive a MAC CE with thebroadcast delay time, the UE 102 may regard it as a negativeacknowledgement.

In some implementations, the NR gNB 104 may send a MAC CE including afield “B” to indicate a “broadcast monitoring duration” within an MSG4.FIG. 15 shows a MAC CE 1500 including a field “B” 150 for indicating thebroadcast monitoring duration, according to an example implementation ofthe present application. In one implementation, the broadcast monitoringduration may be indicated by DCI. The broadcast monitoring duration mayrepresent the number of SI-windows and/or the number of modificationperiods the UE 102 needs to monitor for the SI acquisition. Once the UE102 receives the broadcasting monitoring duration, the UE 102 maymonitor a duration, e.g., a certain number (whose value is indicated bybroadcast monitoring duration) of SI-windows or modification periods,for SI acquisition. In one implementation, a new value of an LCID may beneeded to represent the MAC CE 1500 including the field “B” 150. TheLCID may be placed in the MAC subheader associated with the MAC CE 1500.In the example shown in FIG. 15, the field “B” 150 may be an octethaving a bit width of 8. In other implementations, the bit number of thebroadcast monitoring duration may not be limited to a fixed bit width,e.g., the bit width may be extended or shrunk. In one implementation, ifthe UE 102 receives a MAC CE with the broadcast monitoring duration, theUE 102 may regard it as positive acknowledgement. If the UE 102 does notreceive a MAC CE with the broadcast monitoring duration, the UE 102 mayregard it as negative acknowledgement.

In one implementation, the NR gNB 104 may send a MAC CE including afield “UL Grant” to indicate the uplink resources for the UE 102 withinan MSG4. FIG. 16 shows a MAC CE 1600 including a field “UL Grant” 160for indicating the uplink resources for a UE, according to an exampleimplementation of the present application. In one implementation, such“UL Grant” may be indicated by one of the DCI formats to indicate theuplink resources for the UE 102. Once the UE 102 receives the UL grant,the UE 102 may transmit additional information (e.g., PLMN information,UE ID, I-RNTI, UE specific information) to the NR gNB 104 on the uplinkresources indicated by the UL Grant. In one implementation, a new valueof an LCID may be needed to represent the MAC CE 1600 including thefield “UL Grant” 160. The LCID may be placed in the MAC subheaderassociated with the MAC CE 1600. In the example shown in FIG. 16, thefield “UL Grant” 160 may be an octet having a bit width of 8. In otherimplementations, the bit number of the UL Grant may not be limited to afixed bit width, e.g., the bit width may be extended or shrunk. In oneimplementation, if the UE 102 receives a MAC CE with the UL Grant, theUE may regard it as positive acknowledgement. If the UE 102 does notreceive a MAC CE with the UL Grant, the UE 102 may regard it as negativeacknowledgement.

In one implementation, the NR gNB 104 may send a MAC CE including afield “DL Grant” to indicate the downlink resources for the UE 102within an MSG4. FIG. 17 shows a MAC CE 1700 including a field “DL Grant”170 for indicating the downlink resources for a UE, according to anexample implementation of the present application. In oneimplementation, such “DL Grant” may be indicated by one of the DCIformats to indicate the downlink resources for the UE 102. Once the UE102 receives the DL grant, the UE 102 may receive system information(either via broadcast or via unicast) from the NR gNB 104 on thedownlink resources indicated by the DL Grant. In one implementation, theDL Grant may further include the SI-RNTI for the UE 102 to receive thesystem information. In one implementation, a new value of an LCID may beneeded to represent the MAC CE 1700 including the field “DL Grant” 170.The LCID may be placed in the MAC subheader associated with the MAC CE1700. In the example shown in FIG. 17, the field “DL Grant” 170 may bean octet having a bit width of 8. In other implementations, the bitnumber of the DL Grant may not be limited to a fixed bit width, e.g.,the bit width may be extended or shrunk. In one implementation, if theUE 102 receives a MAC CE with the DL Grant, the UE 102 may regard it aspositive acknowledgement. If the UE 102 does not receive a MAC CE withthe DL Grant, the UE 102 may regard it as negative acknowledgement. Inone implementation, the MAC CE with the DL Grant or the DCI format toindicate the DL Grant may not be limited to be sent in the MSG4.

In one implementation, the NR gNB 104 may send at least one of abroadcast delay time, a broadcast monitoring duration, a UL Grant, and aDL Grant within an MSG4 to the UE 102. FIG. 18 shows a MAC CE 1800including fields “D” 141, “B” 151, “UL Grant” 161, and “DL Grant” 171,according to an example implementation of the present application. Thebroadcast delay time may indicate the beginning time for an SIacquisition procedure to the UE 102. The broadcast monitoring durationmay indicate the duration for the SI acquisition to the UE 102. The ULGrant may indicate the uplink resources for the UE 102 to send moreinformation queried by the NR gNB 104. For example, the UE may send theUE-specific information to the NR gNB 104. The DL Grant may indicate thedownlink resources for the UE 102 to receive the unicast/broadcastsystem information. In one implementation, a new value of an LCID may beneeded to represent the MAC CE 1800 including at least one of the fields“B” 151, “D” 141, “UL Grant” 161, and “DL Grant” 171. The LCID may beplaced in the MAC subheader associated with the MAC CE 1800. In theexample shown in FIG. 18, the field “B” 151 and the field “D” 141 mayboth have a bit width of 4, and the field “UL Grant” 161 and the field“DL Grant” 171 may both have a bit width of 8. In other implementations,the bit width of each field may be extended or shrunk. In oneimplementation, if the UE 102 receives a MAC CE with at least one of thebroadcast delay time, the broadcast monitoring period, the UL Grant, andthe DL Grant, the UE 102 may regard it as positive acknowledgement. Ifthe UE 102 does not receive a MAC CE with at least one of the broadcastdelay time, the broadcast monitoring period, the UL Grant, and the DLGrant, the UE 102 may regard it as negative acknowledgement.

There may be various implementations regarding how the NR gNB 104 sendsa positive/negative acknowledgement in an MSG4 in response to receptionof an MSG3 (which may include the RRC message (e.g.,RRCSystemInfoRequest message) as a CCCH SDU).

Case #6-1: The MAC CE may include at least one bit “A/N” to indicatewhether the MSG3 is successfully received by the NR gNB 104. Forexample, the bit “A/N” being ‘1’ may indicate a positiveacknowledgement, and ‘0’ may indicate a negative acknowledgement. FIG.19 shows a MAC CE 1900 including fields “D” 142, “B” 152, “UL Grant”162, “DL Grant” 172, and “A/N” 182 for indicating acknowledgment,according to an example implementation of the present application.

Case #6-1-1: The rest of the bits in the MAC CE 1900, which includes atleast one bit for acknowledgement of the MSG3, may be reserved forfurther/reserved use. These bits may be padding bits. For example, thefields “B” 152, “D” 142, “UL Grant” 162 and “DL Grant” 172 in FIG. 19may be padding bits or all zeros for further/reserved use. In oneimplementation, a new value of an LCID may be needed to represent theMAC CE 1900. The LCID may be placed in the MAC subheader associated tothe MAC CE 1900.

Case #6-1-2: The rest of the bits in the MAC CE 1900, which includes atleast one bit for acknowledgement of the MSG3, may be used to representat least one of the broadcast delay time (the “D” field 142), thebroadcast monitoring duration (the “B” field 152), the UL Grant field162, and the DL Grant field 172, as shown in FIG. 19. In the exampleshown in FIG. 19, the field “A/N” 182 may have a bit width of 1, thefield “B” 152 may have a bit width of 3, the field “D” 142 may have abit width of 4, and the field “UL Grant” 162 and the field “DL Grant”172 may both have a bit width of 8. In other implementations, the bitwidth of each field may be extended or shrunk. In one implementation, anew value of an LCID may be needed to represent the MAC CE 1900. TheLCID may be placed in the MAC subheader associated to the MAC CE 1900.

In one implementation, a MAC CE including a UE Contention ResolutionIdentity (also referred to as the UE Contention Resolution Identity MACCE) may be utilized to be the positive/negative acknowledgement for theMSG3. The UE Contention Resolution Identity MAC CE may have a fixedW-bit size (e.g., W=48). The field of the UE Contention ResolutionIdentity may contain a UL CCCH SDU (e.g., including the RRC message(e.g., RRCSystemInfoRequest message)). If the UE 102 receives a MAC CEhaving the UE Contention Resolution Identity that matches a portion of(e.g., the first W bits of) the UL CCCH SDU including the RRC message(e.g., RRCSystemInfoRequest message), the UE 102 may regard it as apositive acknowledgement. In one implementation, in a case of a positiveacknowledgment, a MAC entity of the UE 102 may indicate reception of anacknowledgement for the RRC message (e.g., RRCSystemInfoRequest message)to an upper layer entity (e.g., RRC entity) of the UE 102.

In one implementation, at least one of the fields “B”, “D”, “UL Grant”,and “DL Grant” may be added to the MAC CE after the UE ContentionResolution Identity. FIG. 20 shows a MAC CE 2000 including fields “D”143, “B” 153, “UL Grant” 163, “DL Grant” 173, and the UE contentionresolution identity 193, according to an example implementation of thepresent application. In the example shown in FIG. 20, each of the fields“D” 143, “B” 153, “UL Grant” 163, “DL Grant” 173 may have a bit width of8, and the field UE contention resolution identity 193 may have a bitwidth of 48. In other implementations, the bit width of each field maybe extended or shrunk. If the UE 102 receives the UE ContentionResolution Identity MAC CE with at least one of the fields “B”, “D”, “ULGrant” and “DL Grant”, the UE 102 may further know at least one of thesettings of the broadcast delay time, the broadcast monitoring duration,the UL Grant to send additional information, and the DL Grant to receiveunicast/broadcast system information.

Case #7-1: In one implementation, a new LCID may be needed for a UEContention Resolution Identity MAC CE with at least one of the fields“B”, “D”, “UL Grant” and “DL Grant”.

Case #7-2: In one implementation, the LCID of the UE ContentionResolution Identity MAC CE may be reused and one bit (e.g., thereservation bit) in the MAC subheader may be used to indicate/associatefor such UE Contention Resolution Identity MAC CE with at least one ofthe fields “B”, “D”, “UL Grant” and “DL Grant”.

Case #7-3: In one implementation, the LCID and MAC subheader of the UEContention Resolution Identity MAC CE may be reused for a UE ContentionResolution Identity MAC CE with at least one of the fields “B”, “D”, “ULGrant” and “DL Grant”. For UEs in an RACH procedure waiting for the MSG4reception, the UEs may ignore at least one of the fields “B”, “D”, “ULGrant” and “DL Grant”. For UEs in an RACH procedure waiting for the MSG4reception, at least one of the fields “B”, “D”, “UL Grant” and “DLGrant” may be set to a predefined value. For UEs in an RACH procedurewaiting for the MSG4 reception, the NR gNB 104 may not include any bitsfor at least one of the fields “B”, “D”, “UL Grant” and “DL Grant”. ForUEs sending the RRC message (e.g., RRCSystemInfoRequest message) andwaiting for the MSG4 reception, the UEs may follow the indication fromat least one of the fields “B”, “D”, “UL Grant” and “DL Grant” for SIacquisition procedure.

FIG. 21 is a flowchart for a method of wireless communications performedby a UE, according to an example implementation of the presentapplication. The method 2100 may include actions 2102, 2104, 2106 and2108. In action 2102, the UE may receive a random access response fromthe cell. For example, the random access response may be an MSG2 in anMSG3-based on-demand system information request procedure. In action2104, the UE may send a first message (e.g. MSG3) including a CCCH SDUto the cell. The CCCH SDU may include an RRC SI request message (e.g.,RRCSystemInfoRequest message). In action 2106, the UE may receive a MACCE (e.g. MSG4) from the cell. The MAC CE may include a UE contentionresolution identity. One implementation of the MAC CE including the UEcontention resolution identity may be referred to FIG. 20. In action2108, a MAC entity of the UE may indicate reception of an acknowledgmentfor the RRC SI request message to an upper layer entity of the UE (e.g.,the RRC entity of the UE) when the UE contention resolution identity inthe MAC CE matches a portion of (e.g., the starting W bits of) the CCCHSDU in the first message. W is equal to 48 in the example shown in FIG.20, but may also be other positive integers in other implementations.

In one implementation, once the UE 102 successfully receives the MSG4(e.g., at least the DCI and/or MAC CE) in response to the MSG3, the UE102 may further send a message (e.g. MSG5, RRC message, RRC SI requestcomplete message, RRC connection setup complete message) to transmit therequired information to complete the RRC Connection Setup procedure. Forexample, the required information in the message (e.g. MSG5) may includeat least one of the following: a UE ID, an Inactive-Radio NetworkTemporary Identifier (I-RNTI), PLMNinformation/indicator/identity/index/bitmap, a registered MobilityManagement Entity(MME)/Access and Mobility Management Function (AMF),dedicated Non-Access Stratum (NAS) information, an SAE-Temporary MobileSubscriber Identity((5G)-S-TMSI). The UE 102 may transmit theinformation on the uplink resources indicated by the UL Grant in theMSG4 (e.g., a MAC CE, a DCI format). Thus, it is possible that the UE102 may enter an RRC_CONNECTED state after the UE 102 transmits theinformation and completes the RRC connection setup procedure.

It should be noted that the content of the “MAC CE” in some of theimplementations in this disclosure may also be applied for the “MACpayload” or the “MAC RAR”.

In one implementation, the preambles and/or random access resourcesindicated in the si-Request-Config IE in the SIB1 may be associated tothe PLMN-specific information. For example, these resources may beassociated to PLMN information, PLMN-specific SI messages, orPLMN-specific SIBs. FIG. 22 is a sequence diagram illustrating a processof system information request and response, according to an exampleimplementation of the present application. The method 2200 may includeactions 220 and 222. In one implementation, the UE 102 may request thesystem information using an MSG1-based approach. For example, as shownin FIG. 22, in action 220, the UE 102 may send random access resourcesto the NR gNB 104. The NR gNB 104 may realize the requested PLMNinformation, PLMN-specific SI messages, or PLMN-specific SIBs based onthe configured (dedicated) RA (random access) resources on which apreamble is received, or the configured (dedicated) preamble received.In action 222, the NR gNB 104 may send PLMN-specific system informationto the UE 102. In one implementation, the same preamble may be assignedfor one specific SI request, but the NR gNB 104 may further providedifferent PRACH slots to different PLMN-specific SI requests. Bytransmitting the preamble at one dedicated PRACH slot, the NR gNB 104may know the PLMN-specific information toward the SI requested by the UE102. Alternatively, an implicit PRACH resources assignment may be used.For example, the fact that the UE 102 transmits the dedicated preambleat the first ordering PRACH resources in the slot may refer to thesituation that the first PLMN info (ordering by supported PLMNinformation broadcast in the minimum SI) is requested. The UE 102 mayreceive the PLMN-specific system information after the random accessresources and/or preambles transmission.

In one implementation, if the UE 102 receives the negativeacknowledgement from the NR gNB 104, the UE 102 may initiate an SIrequest (e.g., an RRCSystemInfoRequest message, sending the randomaccess resources (e.g., preamble)) again. In one implementation, if theUE 102 cannot receive the system information within the time durationindicated by at least one of the broadcast delay time, the broadcastmonitoring duration and the DL Grant, the UE 102 may initiate an SIrequest (e.g., an RRCSystemInfoRequest message, sending the randomaccess resources (e.g., preamble)) again.

In one implementation, based on the UE 102's RRC state, the NR gNB 104may reply the requested system information in different ways. If the UE102 is in an RRC_CONNECTED state, the NR gNB 104 may reply the systeminformation with dedicated signaling (e.g., via unicast). If the UE 102is in an RRC_IDLE state or an RRC_INACTIVE state, the NR gNB 104 mayreply the system information via broadcast. The pattern of broadcast maybe one shot or periodic within a certain duration.

It should be noted that the NR gNB or the cell mentioned in thedisclosure may be applied to any base station, regardless the radioaccess technologies.

It should be noted that the implementations describing the PLMN-specificsystem information signaling structure in the disclosure are not limitedto the other SI delivery approach (e.g., on demand). Some aspects of thepresent implementations may also be applied for the system informationbroadcast periodically.

FIG. 23 illustrates a block diagram of a node for wirelesscommunication, in accordance with various aspects of the presentapplication. As shown in FIG. 23, node 2300 may include transceiver2320, processor 2326, memory 2328, one or more presentation components2334, and at least one antenna 2336. Node 2300 may also include a RadioFrequency (RF) spectrum band module, a base station communicationsmodule, a network communications module, and a system communicationsmanagement module, input/output (I/O) ports, I/O components, and powersupply (not explicitly shown in FIG. 23). Each of these components maybe in communication with each other, directly or indirectly, over one ormore buses 2340.

Transceiver 2320 having transmitter 2322 and receiver 2324 may beconfigured to transmit and/or receive time and/or frequency resourcepartitioning information. In some implementations, transceiver 2320 maybe configured to transmit in different types of subframes and slotsincluding, but not limited to, usable, non-usable and flexibly usablesubframes and slot formats. Transceiver 2320 may be configured toreceive data and control channels.

Node 2300 may include a variety of computer-readable media.Computer-readable media can be any available media that can be accessedby node 2300 and include both volatile and non-volatile media, removableand non-removable media. By way of example, and not limitation,computer-readable media may comprise computer storage media andcommunication media. Computer storage media includes both volatile andnon-volatile, removable and non-removable media implemented in anymethod or technology for storage of information such ascomputer-readable instructions, data structures, program modules orother data.

Computer storage media includes RAM, ROM, EEPROM, flash memory or othermemory technology, CD-ROM, digital versatile disks (DVD) or otheroptical disk storage, magnetic cassettes, magnetic tape, magnetic diskstorage or other magnetic storage devices.

Computer storage media does not comprise a propagated data signal.Communication media typically embodies computer-readable instructions,data structures, program modules or other data in a modulated datasignal such as a carrier wave or other transport mechanism and includesany information delivery media. The term “modulated data signal” means asignal that has one or more of its characteristics set or changed insuch a manner as to encode information in the signal. By way of example,and not limitation, communication media includes wired media such as awired network or direct-wired connection, and wireless media such asacoustic, RF, infrared and other wireless media. Combinations of any ofthe above should also be included within the scope of computer-readablemedia.

Memory 2328 may include computer-storage media in the form of volatileand/or non-volatile memory. Memory 2328 may be removable, non-removable,or a combination thereof. Example memory includes solid-state memory,hard drives, optical-disc drives, and etc. As illustrated in FIG. 23,memory 2328 may store computer-readable, computer-executableinstructions 2332 (e.g., software codes) that are configured to, whenexecuted, cause processor 2326 to perform various functions describedherein, for example, with reference to FIGS. 1 through 22.Alternatively, instructions 2332 may not be directly executable byprocessor 2326 but be configured to cause node 2300 (e.g., when compiledand executed) to perform various functions described herein.

Processor 2326 may include an intelligent hardware device, e.g., acentral processing unit (CPU), a microcontroller, an ASIC, and etc.Processor 2326 may include memory. Processor 2326 may process data 2330and instructions 2332 received from memory 2328, and information throughtransceiver 2320, the base band communications module, and/or thenetwork communications module. Processor 2326 may also processinformation to be sent to transceiver 2320 for transmission throughantenna 2336, to the network communications module for transmission to acore network.

One or more presentation components 2334 presents data indications to aperson or other device. Exemplary one or more presentation components2334 include a display device, speaker, printing component, vibratingcomponent, and etc.

From the above description, it is manifest that various techniques canbe used for implementing the concepts described in the presentapplication without departing from the scope of those concepts.Moreover, while the concepts have been described with specific referenceto certain implementations, a person of ordinary skill in the art mayrecognize that changes can be made in form and detail without departingfrom the scope of those concepts. As such, the described implementationsare to be considered in all respects as illustrative and notrestrictive. It should also be understood that the present applicationis not limited to the particular implementations described above, butmany rearrangements, modifications, and substitutions are possiblewithout departing from the scope of the present disclosure.

What is claimed is:
 1. A method for receiving system information performed by a user equipment (UE), the method comprising: receiving a system information block type 1 (SIB1) from a cell; wherein the SIB1 comprises a first list, a number of entries in the first list ranges from one to a number of public land mobile networks (PLMNs) operating the cell, and each entry in the first list comprises: an indicator corresponding to a PLMN operating the cell; and access control information of the PLMN operating the cell.
 2. The method of claim 1, wherein the SIB1 further comprises a second list, a number of entries in the second list ranges from one to the number of PLMNs operating the cell, and each entry in the second list comprises: a PLMN identity; a cell identity; and a tracking area code.
 3. The method of claim 1, further comprising: receiving a random access response from the cell; sending a first message comprising a common control channel (CCCH) service data unit (SDU) to the cell, wherein the CCCH SDU comprises a radio resource control (RRC) system information (SI) request message; receiving a medium access control (MAC) control element (CE) from the cell, wherein the MAC CE comprises a UE contention resolution identity; and indicating, by a MAC entity of the UE, reception of an acknowledgment for the RRC SI request message to an upper layer entity of the UE when the UE contention resolution identity in the MAC CE matches a portion of the CCCH SDU in the first message.
 4. The method of claim 3, wherein the RRC SI request message is sent via a CCCH, which is configured with a transparent mode radio link control (RLC) entity, with a Signaling Radio Bearer 0 (SRB0).
 5. The method of claim 3, further comprising: starting a timer after receiving the MAC CE; wherein the RRC SI request message comprises information related to the timer.
 6. The method of claim 3, wherein the MAC CE further comprises at least one of the following: a broadcast delay time; a broadcast monitoring duration; an uplink (UL) grant; and a downlink (DL) grant.
 7. The method of claim 3, further comprising: sending a second message to complete an RRC connection setup procedure, wherein the second message comprises at least one of the following: a UE ID; an inactive radio network temporary identifier (I-RNTI); PLMN information; a registered Mobility Management Entity (MME) or Access and Mobility Management Function (AMF); dedicated non-access stratum (NAS) information; and a System Architecture Evolution (SAE)-Temporary Mobile Subscriber Identity (S-TMSI).
 8. The method of claim 1, wherein the SIB1 further comprises a cell-specific information element.
 9. The method of claim 1, wherein the SIB1 further comprises scheduling information indicating whether each SI message is broadcast or not.
 10. The method of claim 9, wherein the scheduling information further indicates PLMN information corresponding to each SI message.
 11. A user equipment (UE), comprising: one or more non-transitory computer-readable media having computer-executable instructions embodied thereon; and at least one processor coupled to the one or more non-transitory computer-readable media, and configured to execute the computer-executable instructions to: receive a system information block type 1 (SIB1) from a cell; wherein the SIB1 comprises a first list, a number of entries in the first list ranges from one to a number of public land mobile networks (PLMNs) operating the cell, and each entry in the first list comprises: an indicator corresponding to a PLMN operating the cell; and access control information of the PLMN operating the cell.
 12. The UE of claim 11, wherein the SIB1 further comprises a second list, a number of entries in the second list ranges from one to the number of PLMNs operating the cell, and each entry in the second list comprises: a PLMN identity; a cell identity; and a tracking area code.
 13. The UE of claim 11, wherein the at least one processor is further configured to execute the computer-executable instructions to: receive a random access response from the cell; send a first message comprising a common control channel (CCCH) service data unit (SDU) to the cell, wherein the CCCH SDU comprises a radio resource control (RRC) system information (SI) request message; receive a medium access control (MAC) control element (CE) from the cell, wherein the MAC CE comprises a UE contention resolution identity; and indicate, by a MAC entity of the UE, reception of an acknowledgment for the RRC SI request message to an upper layer entity of the UE when the UE contention resolution identity in the MAC CE matches a portion of the CCCH SDU in the first message.
 14. The UE of claim 13, wherein the RRC SI request message is sent via a CCCH, which is configured with a transparent mode radio link control (RLC) entity, with a Signaling Radio Bearer 0 (SRB0).
 15. The UE of claim 13, the at least one processor is further configured to execute the computer-executable instructions to: start a timer after receiving the MAC CE; wherein the RRC SI request message comprises information related to the timer.
 16. The UE of claim 13, wherein the MAC CE further comprises at least one of the following: a broadcast delay time; a broadcast monitoring duration; an uplink (UL) grant; and a downlink (DL) grant.
 17. The UE of claim 13, the at least one processor is further configured to execute the computer-executable instructions to: send a second message to complete an RRC connection setup procedure, wherein the second message comprises at least one of the following: a UE ID; an inactive radio network temporary identifier (I-RNTI); PLMN information; a registered Mobility Management Entity (MME) or Access and Mobility Management Function (AMF); dedicated non-access stratum (NAS) information; and a System Architecture Evolution (SAE)-Temporary Mobile Subscriber Identity (S-TMSI).
 18. The UE of claim 11, wherein the SIB1 further comprises a cell-specific information element.
 19. The UE of claim 11, wherein the SIB1 further comprises scheduling information indicating whether each SI message is broadcast or not.
 20. The UE of claim 19, wherein the scheduling information further indicates PLMN information corresponding to each SI message. 